2016 Fiat 500X: Generation X Published on April 21, 2015 in First Drives by Alain Morin Photo: Alain Morin Single-piston disc brakes on all four wheels. The front-wheel drive Trekking comes with Continental ProContact 225/45R18 tires. The Trekking Plus is equipped with Continental ProContact 225/55R18 tires.